The Australian Technical Advisory Group on Immunisation (ATAGI) cannot rule out four or five doses for COVID-19 vaccines for Australians to be “up to date.” The chair for ATAGI, Nigel Crawford said that his organisation will continue to monitor data from other countries administering four doses at the senate hearing on Feb. 16. ATAGI announced a change of definition for “fully vaccinated” from two doses to three doses on Feb. 10, and the Australians who have yet to receive their third have 6 months’ to get their vaccinations. Crawford, however, said on Feb. 16 in front of the Senate Estimates committee that some immunocompromised patients have already been recommended four doses. Studies in the UK have shown that some immunocompromised patients do not have an adequate immune response to the virus with some activity only detected after the fourth dose. However, with the recent US study showing reduced effectiveness of all …